Genotyping and Phenotyping the Hepatitis C Drug Target NS5A

描述（由申请人提供）： 目标：丙型肝炎病毒（HCV）危害了大量的退伍军人管理局（VA）的患者，治疗是复杂的许多不同的病毒株。我们建议研究病毒遗传学在治疗反应中的作用，特别是HCV如何对称为亲环素抑制剂的抗病毒药物产生反应，这些药物对HCV和HIV具有活性。我们将确定患者体内HCV遗传学的变化如何改变可能预测亲环素抑制剂反应的细胞和生化检测。我们还将在患有HCV的VA患者中试行第一个重要病毒株目录。 研究设计和方法：我们将利用一个大的HCV感染的肝移植人群，有移植前和移植后的样本，以确定是否最早版本的亲环素抑制剂（环孢素），已经在移植患者中使用的目的以外的抗病毒品种HCV耐药性。我们将使用无细胞研究来确定细胞亲环蛋白如何与两种病毒蛋白NS 5A和NS 5 B相互作用，以及病毒蛋白相互作用如何根据它们是否来自对亲环蛋白抑制剂有反应的HCV菌株而有所不同。我们还将建立一个试验性的HCV基因数据库。该数据库将对VA毒株的重要病毒遗传变异以及它们如何随时间变化进行编目。无论我们的研究结果最终是否导致有意使用亲环素抑制剂治疗HCV，这项研究将揭示对称为非结构蛋白NS 5A的调节病毒蛋白的基本见解，该蛋白不仅是亲环素抑制剂的靶点，也是临床前开发中的其他药物的靶点。 健康状况：HCV是VA和美国肝脏疾病和肝癌的主要原因。通过促进HCV的治愈，我们可以预防VA患者的肝癌和肝病并发症。要做到这一点，不仅需要新的抗病毒药物，而且需要新的治疗策略，鼓励更大的个性化护理。HCV具有极高的遗传多样性。这种病毒多样性水平使得抗HCV药物很可能对某些HCV毒株比其他毒株更有效。换句话说，每种HCV治疗的风险效益比可能受到特定菌株遗传学的影响。最近，一些研究中的药物，甚至一些FDA批准的药物已被证明具有显着的抗HCV活性。但在大多数情况下，如果不是所有情况下，药物的效力和不同HCV毒株的基因序列之间的关系在很大程度上是不确定的。所有的病毒药物靶标都与病毒调节蛋白NS 5A相互作用，NS 5A本身也是一种药物靶标。这些研究将揭示亲环素抑制剂治疗VA HIV/HCV合并感染患者以及HCV单一感染患者的潜在效用。如何将亲环素抑制剂抗病毒药物或其他小分子抑制剂在抗病毒鸡尾酒中最佳配对是一个关键的决定，除了VA以外的行业赞助的试验外，还需要VA特定的数据，以减轻不断上升的HCV疾病负担。 公共卫生相关性： VA目前照顾约210，000例慢性HCV病毒血症患者，这是美国任何一个医疗保健系统中最大的HCV患者群体。由于HCV，VA的肝癌发病率最近增加了近三分之一。HCV也是VA中约10%的非霍奇金淋巴瘤的原因，并且与肝脏以外的疾病相关。VA公共卫生质量管理中心的研究表明，许多VA患者由于药物毒性而不被认为是当前治疗的候选人，并且相对于行业赞助的试验，退伍军人的治疗结果令人失望。许多退伍军人，特别是越战时期的退伍军人，由于在战斗任务期间输血而感染了HCV。治疗HCV的费用也很高，全国每年估计超过7亿美元。由于终末期肝病患者的护理成本很高，预计未来十年与HCV相关的成本将上升。因此，如果能够提供新的、更可预测的有效治疗，HCV成本的上升可能会逆转，类似于新的药物组合对HIV护理成本的影响。这项研究探讨了一类新的抗病毒药物-亲环素抑制剂-如何作用于HCV，重点是病毒遗传学如何影响疗效。我们还建议为VA开发第一个HCV病毒遗传数据库，以深入了解HCV遗传学如何影响治疗反应。该数据库将对需要用亲环素抑制剂等抗病毒药物靶向的HCV VA毒株以及目前主要在VA以外进行研究的其他毒株进行编目。

DESCRIPTION (provided by applicant): AIMS: Hepatitis C Virus (HCV) harms a substantial number of Veterans Administration (VA) patients, and therapy is complicated by many different strains of the virus. We propose to study the role of viral genetics in response to therapy, particularly in how HCV responds to antivirals called cyclophilin inhibitors that have activity against HCV and HIV. We will determine how changes in HCV genetics that happen in patients alter cellular and biochemical tests that may predict response to cyclophilin inhibitors. We will also pilot the first catalog of important viral strains in VA patients with HCV. RESEARCH DESIGN & METHODS: We will capitalize on a large HCV-infected liver transplant population that have pre- and post-transplant samples to determine if the earliest version of a cyclophilin inhibitor (cyclosporine) that is already in use in transplant patients for purposes other than as an antiviral breeds HCV resistance. We will use cell-free studies to determine how cellular cyclophilin proteins interact with two viral proteins NS5A and NS5B and how viral protein interactions differ depending upon whether they are from strains of HCV that respond to cyclophilin inhibitors or not. We will also generate a pilot HCV genetic database. The database will catalog important viral genetic variation from strains in the VA and how they change over time. Whether or not our results ultimately lead to the intentional use of cyclophilin inhibitors to treat HCV, this research will reveal fundamental insights into the regulatory viral protein called nonstructural protein NS5A, which is the target of not only cyclophilin inhibitors, but also of other drugs in preclinical development. HEALTH RELATEDNESS: HCV is the major cause of liver disease and liver cancer in the VA and the US in general. By facilitating the cure of HCV, we can prevent the complications of liver cancer and liver disease in VA patients. To do this, not only are new antivirals needed, but also new treatment strategies that encourage greater individualization of care. HCV has an extremely high genetic diversity. That level of viral diversity makes it highly likely that anti-HCV drugs will be more active against some HCV strains than others. In other words, the risk-benefit ratio of each HCV treatment is likely influenced by the genetics of the specific strain. Recently, several investigational and even some FDA-approved drugs have been shown to have significant anti-HCV activity. But in most, if not all, cases, the relationship between the drug's potency and the genetic sequence of different HCV strains is largely undetermined. All of the viral drug targets interact with the viral regulatory protein NS5A, which is itself also a drug target. These studies will shed insight into the potential utility of cyclophilin inhibitors to treat VA HIV/HCV co-infected patients as well as HCV mono-infected patients. How cyclophilin inhibitor antivirals or other small molecule inhibitors should be optimally paired together in antiviral cocktails is a crucial decision that requires VA-specific data, in addition to industry-sponsored trials outside the VA in order to lessen the rising HCV burden of disease. PUBLIC HEALTH RELEVANCE: The VA currently cares for ~210,000 patients with chronic HCV viremia, the largest population of HCV patients in any one US health care system. Due to HCV, the rate of liver cancer in the VA increased by almost a third recently. HCV is also responsible for ~ 10% of NonHodgkins lymphoma in the VA and is associated with diseases outside the liver. Research from the VA's Center for Quality Management in Public Health among other VA sites shows both that many VA patients are not considered candidates for current therapy due to drug toxicities, and that therapeutic results in veterans are disappointing relative to industry-sponsored trials. Many veterans, particularly Vietnam-era veterans contracted HCV due to transfusions during combat duty. The cost of caring for HCV is also substantial with an estimate of over $700 million annually nationwide. Due to the high cost of care for patients with end-stage-liver disease, the cost associated with HCV is expected to rise over the next decade. Therefore if new, more predictably effective therapy can be offered, the rising cost of HCV may be reversed, similar to what new drug combinations did for the cost of HIV care. This study explores how a new class of antivirals -- cyclophilin inhibitors -- acts on HCV, with a focus on how viral genetics influences efficacy. We also propose to develop the first HCV viral genetic database for the VA that will give insight into how HCV genetics impacts treatment response. This database will catalog VA strains of HCV that need to be targeted by antivirals like cyclophilin inhibitors as well as others that are currently being investigated mostly outside the VA.